Lepton electric dipole moments in supersymmetric type II seesaw model

TL;DR

This paper investigates how CP violation in a supersymmetric type II seesaw model influences lepton electric dipole moments, revealing a proportional relationship between muon and electron EDMs across various parameters.

Contribution

It demonstrates that the CP violating phase associated with SU(2)_W triplets significantly affects lepton EDMs through threshold corrections, establishing a predictable ratio between muon and electron EDMs.

Findings

Muon and electron EDM ratio matches their mass ratio in many scenarios.

Threshold corrections at the seesaw scale dominate the EDM contributions.

The model links CP violation to observable EDM ratios.

Abstract

We study the lepton electric dipole moments in the framework of the supersymmetric type II seesaw model where the exchange of heavy SU(2)_W triplets generates small neutrino masses. We show that the CP violating phase of the bilinear soft supersymmetry breaking term associated with the SU(2)_W triplets contributes to lepton electric dipole moments mainly through threshold corrections to the gaugino masses at the seesaw scale. As a consequence, the ratio of the electric dipole moments of the muon and the electron is the same as the ratio of their masses in a wide region of parameter space.